This invention relates to the field of door security systems. More specifically, this invention relates to an electric strike for securing a door to a door frame.
Electric strikes for securing hinged or swinging doors are well-known in the field of door security systems. The electric strikes are employed with doors having projectable dead bolts or latch bolts that engage the electric strike. The electric strike can be configured to secure the door alone, or in combination with other conventional security systems. The electric strike typically is mounted to the door frame and defines an opening in the jamb face of the door frame for receiving the latch bolt and/or dead bolt from the lock set mounted to the door. The electric strike further defines an opening in the frame face contiguous with the opening in the jamb face of the door frame. A pivotal keeper on the electric strike selectively closes the opening in the frame face. A bolt, projecting from the edge of the door, engages the electric strike through the opening in the jamb face. Actuation of the electric strike unlocks the keeper. The keeper is then pivotable to uncover or open the frame face opening to allow the bolt to swing therethrough, and thereby allow opening of the door. The keeper is pivoted by the door being pushed, whereby the bolt engages the keeper of the strike.
The lock assembly of a conventional electric strike is commonly operated by a solenoid. The solenoid is typically configured to be spring biased, wherein energization of the solenoid overcomes the biasing force of the spring to either lock or unlock the electric strike. In a first configuration, power must be continuously supplied to the solenoid in order to maintain the electric strike in a locked condition. This configuration requires a relatively high and continuous input of energy and therefore typically requires electrical wiring through the doorway from an electric line source.
Similarly, electric strikes configured to unlock upon energization can also require a continuous supply of energy in order to maintain the lock in an unlocked condition. Therefore, particularly in settings where the door is to remain unlocked for a substantial period of time, such as during a conventional work day, electrical energy must nevertheless be continuously provided to the electric strike. This second configuration also therefore requires interconnection to continuous line current through the door frame.